// this may be better. taken from http://drakware.com/?e=3
// it means object won't be used until response received. 
// i.e. it manages a pool of XMLHttpRequest objects. 

var xmlreqs = new Array();

function CXMLReq(freed, responseHandlerFunction) {
	this.freed = freed;
	this.xmlhttp = false;
	this.responseHandler = responseHandlerFunction;
	if (window.XMLHttpRequest) {
		this.xmlhttp = new XMLHttpRequest();
	} else if (window.ActiveXObject) {
		this.xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
	}
}

function xmlreqGET(url, responseHandler) {
	alert("xmlget called with: " + url);
	var pos = -1;
	for (var i=0; i<xmlreqs.length; i++) {
		if (xmlreqs[i].freed == 1) { pos = i; break; }
	}
	if (pos == -1) { pos = xmlreqs.length; xmlreqs[pos] = new CXMLReq(1, responseHandler); }
	if (xmlreqs[pos].xmlhttp) {
		xmlreqs[pos].responseHandler = responseHandler;
		xmlreqs[pos].freed = 0;
		xmlreqs[pos].xmlhttp.open("GET",url,true);
		xmlreqs[pos].xmlhttp.onreadystatechange = function() {
			if (typeof(xmlhttpChange) != 'undefined') { xmlhttpChange(pos); }
		}
		if (window.XMLHttpRequest) {
			xmlreqs[pos].xmlhttp.send(null);
		} else if (window.ActiveXObject) {
			xmlreqs[pos].xmlhttp.send();
		}
	}
}

function xmlreqPOST(url,data, responseHandler) {
	var pos = -1;
	for (var i=0; i<xmlreqs.length; i++) {
		if (xmlreqs[i].freed == 1) { pos = i; break; }
	}
	if (pos == -1) { pos = xmlreqs.length; xmlreqs[pos] = new CXMLReq(1, responseHandler); }
	if (xmlreqs[pos].xmlhttp) {
		xmlreqs[pos].responseHandler = responseHandler;
		xmlreqs[pos].freed = 0;
		xmlreqs[pos].xmlhttp.open("POST",url,true);
		xmlreqs[pos].xmlhttp.onreadystatechange = function() {
			if (typeof(xmlhttpChange) != 'undefined') { xmlhttpChange(pos); }
		}
		xmlreqs[pos].xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
		xmlreqs[pos].xmlhttp.send(data);
	}
}

function xmlhttpChange(pos) {
	if (typeof(xmlreqs[pos]) != 'undefined' && xmlreqs[pos].freed == 0 && xmlreqs[pos].xmlhttp.readyState == 4) {
		if (xmlreqs[pos].xmlhttp.status == 200 || xmlreqs[pos].xmlhttp.status == 304) {
			responseHandler = xmlreqs[pos].responseHandler;
			if (responseHandler != "") {
				eval(responseHandler+"(xmlreqs[pos].xmlhttp.responseText)");
			}
			//handle_response(xmlreqs[pos].xmlhttp.responseXML);
		} else {
			handle_error(xmlreqs[pos].xmlhttp.status);
		}
		xmlreqs[pos].freed = 1;
	}
}

function handle_error(thestatus) {
	//alert("xml stuff has generated an error: " + thestatus);
}